Certain activities, such as mountaineering and skiing, subject participants to reduced pressures. These reduced pressures can lead to what is commonly referred to as mountain sickness, with symptoms including nausea and headache. Other activities, such as diving and deep sea construction, subject participants to elevated pressures. If the participant returns to normal atmospheric pressures too rapidly, the participant may experience the detrimental health effects of decompression sickness.
To treat either mountain sickness or decompression sickness, it is known to place the patient in a high-pressure environment. Hyperbaric chambers are a convenient way to provide such a therapeutic environment. A hyperbaric chamber is a chamber in which a pressure greater than ambient, over and above the range of pressure variation encountered in the course of normal weather fluctuations, can be achieved. U.S. Pat. No. 4,974,829 to Gamow et al. (“Gamow”) and U.S. Pat. No. 5,678,543 to Bower (“Bower”), the disclosures of which are hereby expressly incorporated by reference in their entireties, provide examples of such hyperbaric chambers.
Extant hyperbaric chambers, however, generally require a tradeoff between portability and capacity. That is, higher-pressure hyperbaric chambers tend to be more rigid and less portable, while portable chambers tend to be lower pressure. The hyperbaric chamber of Gamow, for example, is a portable chamber capable of achieving pressures up to about 10 psig, which are suitable for treating mild symptoms of pressure sickness. As one of skill in the art will recognize, higher pressure chambers are useful for treating more severe symptoms of decompression or mountain sickness, as well as for other conditions including carbon monoxide poisoning, wound healing, and burns.
Further, to the extent that a portable chamber is also collapsible, a rigid frame, generally made of metal, is often used to retain the uncompressed chamber in a substantially uncollapsed configuration. This aids in ingress to and egress from the chamber when it is in an unpressurized state (i.e., before or after treatment). Installation of this rigid frame into the chamber may be difficult and time consuming. In addition, an exposed metal frame within the chamber is not aesthetically pleasing and may also be physically uncomfortable for the chamber occupant.
Accordingly, it is desirable to provide a portable hyperbaric chamber that retains a substantially uncompressed shape without the need for a rigid frame. It is further desirable for the portable hyperbaric chamber to be capable of operating at higher pressures, on the order of up to about 22 psig. It is further desirable for the portable hyperbaric chamber to be capable of sustaining still higher pressures so as to provide an operating safety factor and to reduce the likelihood of sudden decompression.